This invention relates to a warning system for filter binding in liquid supplying systems and more particularly to an improved filter warning device and related engine control for an internal combustion engine lubricating system.
It is well known in many forms of lubricating systems to employ a filter for filtering the lubricant that is delivered to the engine components. It is also known to provide arrangements for indicating when the filter becomes clogged. However, all of the systems of the aforenoted type have positioned the filter in the pressure line of the lubricating system and hence the warning device can operate on the substantial pressure differential between the inlet and outlet sides of the filter. In many forms of application, however, it is desirable to position the filter in a non-pressurized portion of the lubricant conduit. Furthermore, many systems employ relatively low pressure or gravity lubrication systems and the prior art type of filter warning devices have not lent themselves to use in such low pressure systems.
It is, therefore, a principal object of this invention to provide an improved filter warning device for a lubricating system.
It is another object of this invention to provide a filter warning arrangement for a low pressure lubricating system.
It is yet another object of this invention to provide a filter warning device for a gravity feed lubricant system.
One form of lubricating system that is becoming widely used is employed in connection with the two-cycle engine of an outboard motor. Although two-cycle engines are normally lubricated by mixing lubricant with the fuel, such arrangements have a number of disadvantages. For example, this type of arrangement requires the operator to premix lubricant with the fuel and thus gives rise to the possibility of the operator forgetting to add lubricant or adding improper amounts of lubricant. In addition, the premix systems normally result in an arrangement wherein a given lubricant to fuel mixture is employed regardless of the running conditions of the engine even though the engine lubricant demands vary.
Recently, it has been proposed to employ a separate lubricating system for a two-cycle outboard motor wherein a separate lubricant reservoir is provided and the lubricant is fed from this reservoir to the engine for its lubrication by means of some form of pumping device. With such an arrangement, it is desirable to provide a filter in the lubricant reservoir for filtering the lubricant that flows from the reservoir to the remotely positioned lubricant pump. However, this type of application has the disadvantage that it is difficult to determine when the lubricant filter becomes clogged. The aforenoted prior art type of warning devices are not usable with this type of a system because of the fact that lubricant flows through the filter by gravity.
It is, therefore, a further object of this invention to provide an improved lubricant system for an outboard motor.
It is another object of this invention to provide an improved warning system for the filter of an outboard motor lubricating system.
As has been previously noted, certain forms of lubricating systems have provided warning devices for indicating when the filter becomes clogged. Although such warning devices are extremely advantageous, they are to no avail if the operator ignores the filter clogged warning signal. Furthermore, the warning may be such that the operator may not notice it and if appropriate action is not taken, the engine or machine lubricated can very well be damaged due to lack of adequate lubricant.
It is, therefore, a further object of this invention to provide an improved lubricating system wherein the device being lubricated is protected in the event of filter clogging.
It is a further object of the invention to provide a lubricating system for an internal combustion engine embodying a filter and wherein the speed of operation of the engine is reduced in the event the filter becomes clogged.